The invention relates to a method for designing a connector between a first and a second element of a dental restoration, such as a connector between a cap (coping hereinafter) and a coping, or a coping and an intermediate element (pontic hereinafter), or a pontic and a pontic of a bridge.
Dental restorations are increasingly produced using CAD/CAM processes. For this, physical models of stumps are scanned and the distribution of measured points subsequently is used to compute models, which are then used in the manufacturing of the dental prosthesis. In this regard, we refer to WO-A-99/47065 and WO-A-03/07834 as examples.
With regard to copings, the respective methods yield extremely satisfactory results. However, the production of connectors poses problems. Thus, state of the art connectors are characterized by quasi-standardized geometries, which consist of tubular sections that are rounded at the ends to be connected to the copings or pontics. If using a hob cutter for this, the ends can be blocked out in order to remove edges.
U.S. Pat. No. 6,049,743 discloses a method for designing dental prostheses such as bridges and crowns. Here, the particular data of a set of teeth is recorded and taken into account when selecting one of a number of stored bridge elements for the dental prosthesis.
A method for fitting a digital set of 3D data of a dental prosthesis element to neighbouring teeth is known from DE-A-10 2005 009 873 (=WO-A-2006/077267), whereby a contact area to the adjacent teeth is defined.
U.S. Pat. No. 5,257,203 describes a method for manipulating a computer-controllable 3D model with ideal geometry to match actual conditions.